Download and Install Android 8.0 Oreo on Samsung Galaxy S4 [AOSP Based]

As it is an old device so it will not get officially android oreo update.But you want to Update Galaxy S4 to Latest Android 8.0 Oreo, you can simply install AOSP custom ROM on their device.

Known issues

• The broken Stock camera app (Workaround: install Camu app from Playstore, Photos, and Videos works fine)
• NFC (removed from build ATM)
• RIL: outgoing calls broken on GSM devices (everything else works fine), completely broken on CDMAs variants (WIP)
• BUG REPORT NOT ALLOWED AT THIS STAGE OF DEVELOPMENT
• CDMA Users:  as we don’t have a CDMA device for testing, so CDMAs variants will be broken forever

Supported variants : I9505, I9505G, I9507, I9508, I337, M919, I545, R970, L720, S970G, S975L.

Pre-Requirements

• Make sure your phone up to 80% charging
• Root your device.
• Make the Backup of important apps, messages, and contacts.
• Must install latest CWM/ TWRP recovery.
• Do not try this guide on any other Android device.
• Download Android 8.0 Oreo AOSP ROM: Link

Steps to install Android 8.0 Oreo on Galaxy S4:

• Firstly, download Android 8.0 Oreo Rom for your Galaxy S4.
• Then change the name to Update.zip.
• Move the ROMto the root of sd card.
• Now turn off your smartphone.
• Boot in recovery mode.
• Now Tap on Wipe, Wipe Dalvik cache, Wipe cache partition, and Wipe data / Factory reset.
• Then tap on Install and choose the Update.zip file that you have downloaded earlier.
• Now confirm the installation and tap on reboot.
• You have successfully Updated Galaxy S4 to Android 8.0 Oreo.

Source